Locking socket



July 22, 1930. M. N. RUSSELL 1,771,009

LOCKING SOCKET Filed May s, 1928 Patented July 22, g 1930 ,IJUNIT D .sTATEs" PATENTQO MARK N. RUSSELL, or sYnlicnsE nnwyonxgnssrcnon 'rorAss -& SEYMOUR SYRACUSE, NEW YORK, ,A conronn'rronor New YORK a F-icEY Locxmq socKET f Application filed Hay 3,

This invention relates to a socket 0r receptacle for incandescent electric lamps, fuses, attachment plugs and thelike'and more par ticularly to a lock mechanism for the preven- 7 tion of the unauthorized removal of such devices as maybe placed in the socket.

It is a general object of the present invention to provide a novel'and improved form of lock socket. 1 a 1 e More particularly .it is an obj ect of the invention to provide alock socketin which the operating member is adapted to be engaged by a suitable insulated key which extends at a slight angle to theaxis of the socket whereby the lock maybe operated even though the socket be in a deep reflector or in a husk and in spite of the size of the lamp in the socket.

A further object of the invention consists in the provision, in a receptacle of the type described, of a prong mounted on a rigid shank resiliently retained in the socket, said prongbeing adapted to be projected through an opening in the screw shell of the socket to engage with the base of theidevice in the socket, together with cam means carried by the prong assemblyandadapted to engage a surface on the outer or enclosing shell of the socketto forcethe prong through the opening upon a rotation of the cam. I

Other and further objects and features of the invention will be more apparent to those skilled in the art uponja consideration of the accompanying drawing and following specification' wherein is disclosed a single, exemplary embodiment of the invention; It is to be understood, however, that such changes may be made'in the invention, as disclosedy-as fall within the scope of the appended claims without departing from the spirit of the invention. I f I In said drawings: p t V Figure'l is a side elevation ofa socket constructed according to the 'present invention,

a portion of the outer and'screw shells being shown in longitudinalcentral section; f

Figure 2 is' a view similar to Fig. 1 but showing the prong in locked position;

Figure ,3 is a transverse sectionon line 3-3 of Fig. 2; I

1928. Serial no. 274,919.

line Hot Fig 1; Figure 5 is a section Fig. 1; and,

I Figure 4 is a transverse section taken on Figure 6 is a perspective ofthelocking i i assembly; a 1 a a Lock sockets of a various types are well known in the art and areintended'to prevent the unauthorized removal of lamps and the like from sockets in public: andrs'emi-public places. Incidentally, suchlock devicesserve to prevent lamps from jarring loose duefto vibrations. The present invention is intend- .ed to simplify such constructions and to eliminate the need of openingsthrough the sides of the socket or enclosing parts such as reflectors, husks and the like. The axis of the lock member is, therefore, set at such an angle to the axis of the socket that the lock' key will I pass along side of a lamp and betweenfsuch lampiand a reflector or husk if present,

Referringnow to the drawings, there is disclosed at 10 a more or less conventional form of lamp receptacle known tothe trade as a reflector type; although it is obvious that the invention may be; applied to various types of receptacles, The receptacle shown has apart 11 which contains the circuit terminals. It is adapted to be attached to the main part 12 bymeansof a pair of longitudinal current-carrying-screws, not shown. I f I Part 12 is preferably molded from a suitable plastic material such: as porcelain to the general configuration shown and is provided with a central cylindrical recess 13 having the substantially flat bottom 14,; In this recess is received and securedthe screw shell contact 15 vof the receptaclaiormd as is customary from apressed or spun tube of conducting material. .This screw shell is provided with an aperture 16 through its threaded side wall near the outer edge thereofthrough which the. lock maypass- The lock mechanism is included in a sin gle prong,.now. about to bedescribed, V

the right angled foot 18 extendin from one sidethere0f. Atthe opposite end 0 the shank fromthe foot is the wing 19. extendingin the opposite direction but from the same side of the shank as the foot. A portion of this wing 19 extends beyond the face of the shank and forms the prong which projects 5 through the aperture 16 to engage with the just slightly less in depth than the thickness 5 of the foot. In assembling the apparatus, the locking assembly is first placed in position with the foot 18 in its depression 23, and then the screw shell isslipped into position and secured against the bottom of the recess by means of suitable screws as 24. In Figures 1 and 2, it will be seen that the bottom of the screw shell rests on the upper surface of the foot and the angle of this foot in respect to the shank 17 is such that the natural resilience of the screw shell, pressing the foot into the bottom of its recess, holds the shank and the prong in the position shown in Figure 1 with the prong withdrawn through the opening 16. Suitable effort applied in the direction of movement of the prong will cause it to pass through the opening 16 rocking the foot in itsrecess and slightly flexing the screw shell. The means for forcing the prong through the opening 16 is a cam arranged against 5 the under face of the wing 19 and attached by any suitable means to the shaft 26 which passes through and is journalled in the wing. Integral with the shaft 26 is the enlarged head 27 having a shoulder which engages with the outer face of the wing. Extending from this head is the integral nut 28, of any desired configuration adapted to be engaged by any suitable type of key to rotate'the cam. As seen in Figure 3 the cam is generally rectangular in configuration, having the flat face 32 which normally rests against the wall 29 of the offset 21 when the prong is in the withdrawn position. On rotating the cam in a counter clockwise direction, as viewed in Fig. 0 3, it moves to the position shown in that figure; so that the flat face 30 engages with this wall 29. This face 30 is further from the axis of the cam shaft than the face 32 and hence the prong is projected through the opening :5 16. A suitably rounded corner connects the faces 32 and 30. A stop wall 31 integral with the part 12 engages the cam when it is in the position shown in Fig. 3 and limits further rotation. This is best shown in Fig. 5.

The advantages of the present type of lock mechanism will be readily evident. In addition to those already mentioned it may be pointed out that the prong has but two positions, locked and unlocked, shown respectively in Figs. 2 and 1. In the unlocked position, the prong is sure to be withdrawn sufiiciently far so as not to interfere with the removal of the lamp, and in the locked position, it is certain to be projected inwardly a sullicient distance to tightly engage and probably cam mounted for movement with said prong and adapted to engage said outer shell when rotated to force said prong through said hole.

2. In a socket for lamps, in combination, an outer shell, a screw shell therein having a hole therethrough, a supporting shank, a prong on said shank adapted-to be projected through said hole and a cam carried by said shank and engageable with said outer shell, when rotated, to force said prong through said hole.

3. In a socket for incandescent lamps, in combination, an insulating base, an outer shell, a screw shell therein having a hole through the threaded portion thereof, a prong adapted to be moved through said hole, a shank supporting said prong, a foot on said shank, engaged between the base of said screw shell and said insulating base, a cam having a shaft rotatable in the'prong end of said shank, said cam being engageable with said outershell, when rotated, to force said prong through said hole and means to rotate said cam.

4;. In a socket for incandescent lamps, in combination, an outer shell, a screw shell therein having a hole through the threaded portion thereof, a prong adapted to be moved through said hole, a shank supporting said prong, means on said shank engaged between the said screwshell and another part of the socket, a cam having a shaft rotatable in the prong end of said shank, said cam being engageable with said outer shell, when rotated, to force said'prong through said hole and means to limit the rotation of said cam.

5. In a socket for incandescent lamps, in combination, an outer shell, a screw shell therein having a hole through the threaded portion thereof, a prong adapted to be moved through said hole, a shank supporting said prong, a foot on said shank in a recess in said outer shell, said screw shell engaging said foot to retain the same in said recess and to bias said shank and prong assembly to maintain said prong out of said hole and means to move said prong through said hole for the purpose described.

6. In a socket for incandescent lamps, in combination, an outer shell, a screw shell therein having a hole through thethreaded therein having a hole through the threaded portion thereof, a shank supporting said prong, a foot on said shank in a recess,-said screw, shell engaging said foot to retain the same in said recess and to bias said shank and prong assembly to maintain said prong out ofsaid hole, a cam carried by said shank and prong assemblyfand engaging said outer shell whereby rotation of said cam will project said prong through said hole and means to rotate said cam.

7. In' a socket for incandescent lamps, in; combinatlon, an outer shell of lnsulating mav terial having a substantially cylindrical'recess therein, a screw shellcontaot secured in said recess and having a hole in the threaded portion thereof, a channel in the cylindrical wall of said recess adjacent said hole, an integral assembly in said channel including a shank and aprong adapted to be projected through said hole, an inturned foot onvsaid shank received in a depression in the bottom wall of said recess, the upper surface of said foot being engaged by said screwshell tobias the prong away from said hole, a cam pivoted to a lip on said shank and'having an eccentric edge adapted to engagea wall-of said channel to move said assembly to pro j set the prong through said hole. 7

8. In a socket for incandescent lamps,.in I 30 combination, a screwshell having a hole therein, a prong adapted to be projected through said hole, rigid means to support said prong, said means being resiliently clamped between and held by said screw shell and an insulating part of said socket.

9. In a socket for incandescent lamps, in

combination, a-nouterv shell, a screw shell portion thereof, a prong adapted to be moved through said hole, a rigid shank supporting said prong, means on said shank clamped'by said screw shell to bias said shank to main-' tain the prong out of the hole and means to move said prong through said hole.

In testimony whereof I hereunto afiix my signature. 7

' MARK N. RUSSELL. 

